학술논문

Measurements of the τ polarisation in Z0 decays
Document Type
Article
Author
Abreu, P.Adam, W.Adye, T.Agasi, E.Ajinenko, I.Aleksan, R.Alekseev, G. D.Allport, P. P.Almehed, S.Almeida, F. M. L.Alvsvaag, S. J.Amaldi, U.Amato, S.Andreazza, A.Andrieux, M. L.Antilogus, P.Apel, W -D.Arnoud, Y.Åsman, B.Augustin, J -E.Augustinus, A.Baillon, P.Bambade, P.Barao, F.Barate, R.Barbiellini, G.Bardin, D. Y.Barker, G. J.Baroncelli, A.Barring, O.Barrio, J. A.Bartl, W.Bates, M. J.Battaglia, M.Baubillier, M.Baudot, J.Becks, K -H.Begalli, M.Beilliere, P.Belokopytov, Yu.Beltran, P.Benvenuti, A. C.Berggren, M.Bertrand, D.Bianchi, F.Bigi, M.Bilenky, M. S.Billoir, P.Bjarne, J.Bloch, D.Blume, M.Blyth, S.Bocci, V.Bolognese, T.Bonesini, M.Bonivento, W.Booth, P. S. L.Borisov, G.Bosio, C.Bostjancic, B.Bosworth, S.Botner, O.Boudinov, E.Bouquet, B.Bourdarios, C.Bowcock, T. J. V.Bozzo, M.Branchini, P.Brand, K. D.Brenner, R. A.Bricman, C.Brillault, L.Brown, R. C. A.Bruckman, P.Brunet, J -M.Bugge, L.Buran, T.Buys, A.Caccia, M.Calvi, M.Camacho Rozas, A. J.Camporesi, T.Canale, V.Canepa, M.Cankocak, K.Cao, F.Carena, F.Carrilho, P.Carroll, L.Caso, C.Cassio, V.Castillo Gimenez, M. V.Cattai, A.Cavallo, F. R.Cerrito, L.Chabaud, V.Charpentier, Ph.Chaussard, L.Chauveau, J.Checchia, P.Chelkov, G. A.Chliapnikov, P.Chochula, P.Chorowicz, V.Cindro, V.Collins, P.Contreras, J. L.Contri, R.Cortina, E.Cosme, G.Cossutti, F.Crawley, H. B.Crennell, D.Crosetti, G.Cuevas Maestro, J.Czellar, S.Dahl-Jensen, E.Dahm, J.Dalmagne, B.Dam, M.Damgaard, G.Daum, A.Dauncey, P. D.Davenport, M.Da Silva, W.Defoix, C.Della Ricca, G.Delpierre, P.Demaria, N.De Angelis, A.De Boeck, H.De Boer, W.De Brabandere, S.De Clercq, C.De La Vaissiere, C.De Lotto, B.De Min, A.De Paula, L.De Saint-Jean, C.Dijkstra, H.Di Ciaccio, L.Djama, F.Dolbeau, J.Donszelmann, M.Doroba, K.Dracos, M.Drees, J.Drees, K. -A.Dris, M.Dufour, Y.Dupont, F.Edsall, D.Ehret, R.Eigen, G.Ekelof, T.Ekspong, G.Elsing, M.Engel, J -P.Ershaidat, N.Espirito Santo, M.Fassouliotis, D.Feindt, M.Ferrer, A.Filippas, T. A.Firestone, A.Foeth, H.Fokitis, E.Fontanelli, F.Formenti, F.Franek, B.Frenkiel, P.Fries, D. C.Frodesen, A. G.Fruhwirth, R.Fulda-Quenzer, F.Furstenau, H.Fuster, J.Gamba, D.Gandelman, M.Garcia, C.Garcia, J.Gaspar, C.Gasparini, U.Gavillet, Ph.Gazis, E. N.Gele, D.Gerber, J -P.Gillespie, D.Gokieli, R.Golob, B.Gopal, G.Gorn, L.Gorski, M.Gracco, V.Grard, F.Graziani, E.Grosdidier, G.Gunnarsson, P.Gunther, M.Guy, J.Haedinger, U.Hahn, F.Hahn, M.Hahn, S.Haider, S.Hajduk, Z.Hakansson, A.Hallgren, A.Hamacher, K.Hao, W.Harris, F. J.Hedberg, V.Henriques, R.Hernandez, J. J.Herquet, P.Herr, H.Hessing, T. L.Higon, E.Hilke, H. J.Hill, T. S.Holmgren, S -O.Holt, P. J.Holthuizen, D.Houlden, M.Hrubec, J.Huet, K.Hultqvist, K.Ioannou, P.Jackson, J. N.Jacobsson, R.Jalocha, P.Janik, R.Jarlskog, G.Jarry, P.Jean-Marie, B.Johansson, E. K.Jonsson, L.Joram, C.Juillot, P.Kaiser, M.Kalmus, G.Kapusta, F.Karlsson, M.Karvelas, E.Katsanevas, S.Katsoufis, E. C.Keranen, R.Khomenko, B. A.Khovanski, N. N.King, B.Kjaer, N. J.Klein, H.Klovning, A.Kluit, P.Koehne, J. H.Koene, B.Kokkinias, P.Koratzinos, M.Kostioukhine, V.Kourkoumelis, C.Kouznetsov, O.Kramer, P. -H.Krammer, M.Kreuter, C.Krolikowski, J.Kronkvist, I.Krumstein, Z.Krupinski, W.Kubinec, P.Kucewicz, W.Kurvinen, K.Lacasta, C.Laktineh, I.Lamblot, S.Lambropoulos, C.Lamsa, J. W.Lanceri, L.Lane, D. W.Langefeld, P.Lapin, V.Last, I.Laugier, J -P.Lauhakangas, R.Leder, G.Ledroit, F.Lefebure, V.Legan, C. K.Leitner, R.Lemoigne, Y.Lemonne, J.Lenzen, G.Lepeltier, V.Lesiak, T.Liko, D.Lindner, R.Lipniacka, A.Lippi, I.Loerstad, B.Lokajicek, M.Loken, J. G.Lopez, J. M.Lopez-Fernandez, A.Lopez Aguera, M. A.Loukas, D.Lutz, P.Lyons, L.MacNaughton, J.Maehlum, G.Maio, A.Maltezos, A.Malychev, V.Mandl, F.Marco, J.Marechal, B.Margoni, M.Marin, J -C.Mariotti, C.Markou, A.Maron, T.Martinez-Rivero, C.Martinez-Vidal, F.Marti i Garcia, S.Matorras, F.Matteuzzi, C.Matthiae, G.Mazzucato, M.Mc Cubbin, M.Mc Kay, R.Mc Nulty, R.Medbo, J.Meroni, C.Meyer, W. T.Miagkov, A.Michelotto, M.Migliore, E.Mirabito, L.Mitaroff, W. A.Mjoernmark, U.Moa, T.Moeller, R.Moenig, K.Monge, M. R.Morettini, P.Mueller, H.Mundim, L. M.Murray, W. J.Muryn, B.Myatt, G.Naraghi, F.Navarria, F. L.Navas, S.Negri, P.Nemecek, S.Neumann, W.Neumeister, N.Nicolaidou, R.Nielsen, B. S.Nijjhar, B.Nikolaenko, V.Niss, P.Nomerotski, A.Normand, A.Oberschulte-Beckmann, W.Obraztsov, V.Olshevski, A. G.Onofre, A.Orava, R.Osterberg, K.Ouraou, A.Paganini, P.Paganoni, M.Pages, P.Palka, H.Papadopoulou, Th. D.Pape, L.Parodi, F.Passeri, A.Pegoraro, M.Pennanen, J.Peralta, L.Pernegger, H.Pernicka, M.Perrotta, A.Petridou, C.Petrolini, A.Phillips, H. T.Piana, G.Pierre, F.Pimenta, M.Plaszczynski, S.Podobrin, O.Pol, M. E.Polok, G.Poropat, P.Pozdniakov, V.Prest, M.Privitera, P.Pullia, A.Radojicic, D.Ragazzi, S.Rahmani, H.Rames, J.Ratoff, P. N.Read, A. L.Reale, M.Rebecchi, P.Redaelli, N. G.Regler, M.Reid, D.Renton, P. B.Resvanis, L. K.Richard, F.Richardson, J.Ridky, J.Rinaudo, G.Ripp, I.Romero, A.Roncagliolo, I.Ronchese, P.Roos, L.Rosenberg, E. I.Rosso, E.Roudeau, P.Rovelli, T.Ruckstuhl, W.Ruhlmann-Kleider, V.Ruiz, A.Rybicki, K.Saarikko, H.Sacquin, Y.Sadovsky, A.Sajot, G.Salt, J.Sanchez, J.Sannino, M.Schneider, H.Schyns, M. A. E.Sciolla, G.Scuri, F.Sedykh, Y.Segar, A. M.Seitz, A.Sekulin, R.Shellard, R. C.Siccama, I.Siegrist, P.Simonetti, S.Simonetto, F.Sisakian, A. N.Sitar, B.Skaali, T. B.Smadja, G.Smirnov, N.Smirnova, O.Smith, G. R.Sokolov, A.Sosnowski, R.Souza-Santos, D.Spiriti, E.Squarcia, S.Staeck, H.Stanescu, C.Stapnes, S.Stavitski, I.Stavropoulos, G.Stepaniak, K.Stichelbaut, F.Stocchi, A.Strub, R.Stugu, B.Szczekowski, M.Szeptycka, M.Tabarelli, T.Tavernet, J. P.Tchikilev, O.Theodosiou, G. E.Tilquin, A.Timmermans, J.Tkatchev, L. G.Todorov, T.Toet, D. Z.Tomaradze, A.Tome, B.Torassa, E.Tortora, L.Transtromer, G.Treille, D.Trischuk, W.Tristram, G.Trombini, A.Troncon, C.Tsirou, A.Turluer, M -L.Tyapkin, I. A.Tyndel, M.Tzamarias, S.Ueberschaer, B.Ueberschaer, S.Ullaland, O.Uvarov, V.Valenti, G.Vallazza, E.Vander Velde, C.Van Apeldoorn, G. W.Van Dam, P.Van Doninck, W. K.Van Eldik, J.Vegni, G.Ventura, L.Venus, W.Verbeure, F.Verlato, M.Vertogradov, L. S.Vilanova, D.Vincent, P.Vitale, L.Vlasov, E.Vodopyanov, A. S.Voutilainen, M.Vrba, V.Wahlen, H.Walck, C.Wehr, A.Weierstall, M.Weilhammer, P.Wetherell, A. M.Wicke, D.Wickens, J. H.Wielers, M.Wilkinson, G. R.Williams, W. S. C.Winter, M.Witek, M.Wormser, G.Woschnagg, K.Yip, K.Yu, L.Yushchenko, O.Zach, F.Zaitsev, A.Zalewska, A.Zalewski, P.Zavrtanik, D.Zevgolatakos, E.Zimin, N. I.Zito, M.Zontar, D.Zuberi, R.Zucchelli, G. C.Zumerle, G.
Source
Zeitschrift für Physik C Particles and Fields; June 1995, Vol. 67 Issue: 2 p183-201, 19p
Subject
Language
ISSN
01709739; 14315858
Abstract
A sample of Z0?t+t- events observed in the DELPHI detector at LEP in 1991 and 1992 is analysed to measure the t polarisation in the exclusive decay channels  $$ev\bar v$$ ,  $$\mu v\bar v$$ , p?, ?? and a1?. The t polarisation is also measured with an inclusive hadronic analysis which benefits from a higher efficiency and a better systematic precision than the use of the exclusive decay modes. The results have been combined with those published on the 1990 data. A measurement of the t polarisation as a function of production angle yields the values for the mean t polarisation t=-0.148±0.022 and for the Z0 polarisationPZ=-0.136±0.027. These results are used to determine the ratio of vector to axial-vector effective couplings for taus  $$\bar v_\tau /\bar a_\tau = 0.074 \pm 0.011$$ , and for electrons  $$\bar v_e /\bar a_e = 0.068 \pm 0.014$$ , compatible with e-t universality. With the assumption of lepton universality, the ratio of vector to axial-vector effective couplings for leptons  $$\bar v_l /\bar a_l = 0.072 \pm 0.008$$ is obtained, implying a value of the effective weak mixing angle sin2?efflept=0.2320±0.0021.